Casting device

ABSTRACT

A device is provided for making castings conforming to a mold while leaving the impression of the casting preserved in the mass of particles of the casting material. There is a casting box containing loose magnetizable particles with which nonmagnetizable particles may be admixed and the casting is carried out through the action of magnetic forces generated either by electromagnets or permanent magnets and the casting action is continued at least until the casting becomes strong enough to be self-supporting. The source of the magnetic forces for carrying out the casting include at least one permanent magnet or electromagnet having one or more pole shoes which are adjustable relative to the casting box. Each magnet may be subdivided into a plurality of individual magnets. The casting box is mounted on guides of non-magnetic material which guides may be directly on the casting box or on the magnets or on their pole shoes. Simplified casting is obtained at reduced cost.

[ 51 May 16,1972

[ CASTING DEVICE [72] Inventor: Fritz Hegewaldt,

Germany Herdecke-Kirchende,

[73] Assignee: Brown, Boveri & Cie Aktiengesellschaft,

Kallstadter Strasse, Mannheim-Kafertal, Germany [22] Filed: Apr. 19,1971 [2|] Appl.No.: 135,406

Related U.S. Application Data [63] Continuation of Ser. No. 783,920,Dec. 16, 1968,

abandoned.

[30] Foreign Application Priority Data Jan. 3, 1968 Germany .P 16 08039.0

[52] U.S. Cl. ..425/3, l8/DIG. 33, 164/349, 264/24, 264/111, 164/148,425/453 [51] Int. Cl. ..B22c 15/00 [58] Field of Search ..264/24,l1l,221; 18/DlG. 33, 18/39; 164/34, 48, 49, 250, 146, 147, 148, 349;

[56] References Cited UNITED STATES PATENTS 2,581,489 l/1952 Kilham..18/DlG.33

3,216,074 1 1/1965 Harrison l 8/DIG. 33

FOREIGN PATENTS OR APPLlCATlON S 1,806,277 6/1970 Germany l 8/DIG. 33

Primary Examiner-Francis S. Husar Assistant Examiner.lames F. Coan [5 7]ABSTRACT A device is provided for making castings conforming to a moldwhile leaving the impression of the casting preserved in the mass ofparticles of the casting material. There is a casting box containingloose magnetizable particles with which non-magnetizable particles maybe admixed and the casting is carried out through the action of magneticforces generated either by electromagnets or permanent magnets and thecasting action is continued at least until the casting becomes strongenough to be self-supporting. The source of the magnetic forces forcarrying out the casting include at least one permanent magnet orelectro-magnet having one or more pole shoes which are adjustablerelative to the casting box. Each magnet may be subdivided into aplurality of individual magnets. The casting box is mounted on guides ofnon-magnetic material which guides may be directly on the casting box oron the magnets or on their pole shoes. Simplified casting is obtained atreduced cost.

5 Claims, 2 Drawing Figures CASTING DEVICE This application is acontinuation of Ser. No. 783,920, filed Dec. 16, 1968, now abandoned.

This invention relates to electromagnetic or magnetic casting wherein apredetermined shape or object is formed conforming to a mold in loosemagnetizable particles which may or may not be mixed withnon-magnetizable particles and under conditions such that the impressionof the cast articles or object remains preserved in the loosemagnetizable particles. The casting is carried out by the application ofmagnetic forces to the magnetizable particles which are disposed in acasting box mounted in a suitable framework through nonmagnetizableconnections. The magnetizable forces are applied until the shape to beproduced from the magnetizable particles is at least strong enough to beself-supporting.

It is known from German Pat. No. 1,959,207 that magnetizable particlesin the form of a loose agglomeration can be cast in a mold by means ofan electrical field created by induction coils until the casting becomessolid. This procedure is recognized as being disadvantageous due to therelatively great cost resulting from the one or more induction coilsdisposed around the casting boxes particularly because the casting boxhas to be manipulated by raising or lowering it when it is introducedinto or removed from circularly closed induction coils. When the castingboxes have been kept stationary in the past it has been necessary tomove the induction coils up and down or relative to the casting boxesand this has been found to be either more complicated or more expensive.

According to the present invention magnetizable particles are cast intoa predetermined or preselected shape or object utilizing generators ofmagnetic fields other than induction coils. In general this isaccomplished by means of one or more magnets each of which has one ormore pole shoes to create the cohesive forces necessary to consolidatethe loose magnetizable casting material particles into the required formof shape. The loose magnetizable particles are not only initiallyunconnected to one another, but they can be admixed withnon-magnetizable particles. Thus, the invention provides an entirely newmeans and method for making magnetic or electromagnetic castings andwithout the use of an induced magnetic field. The cohesive forcesrequired to ring the loose magnetizable particles, with or without theadmixed non-magnetizable particles, into the shape determined by themold cavity can be created either by electromagnets or by permanentmagnets which are highly advantageous and relatively inexpensive ascompared with the prior known use of electrical fields generated byinduction coils which latter are completely eliminated by the presentinvention. The construction of the casting device which is hereinafterdescribed in detail has an advantage that the permanent magnets orelectromagnets may be readily arranged or re-arranged with respect tothe casting material so as to effect casting in the simplest manner andin the shortest period of time and for that purpose the magnets may bearranged opposite any desired surface of the casting box and may bedivided into a plurality of smaller or individual magnets. Furthermore,the casting box is provided with non-magnetic guides or supports whichdo not interfere with the casting operation and which also serve tomaintain the necessary spacing from the magnet to the pole shoes, eachmagnet being provided with one or more pole shoes and all the componentsof the casting device being relatively movable. The non-magnetic guidescan also be arranged either on the casting box or on the magnets or ontheir pole shoes.

In the accompanying drawing which illustrates a preferred embodiment ofthe invention:

FIG. 1 shows a casting device according to the invention incross-sectional view, and

FIG. 2 shows a plan view of FIG. 1.

Referring to the drawing in detail, casting box 1 made of any suitableor known material contains casting material 3 in the form of loosemagnetizable particles of known material with which, if desired anddepending on the particular casting to be produced and the use to whichit is put, may be admixed therewith non-magnetizable particles. Thecasting material 3 has a cavity or mold 4 therein as shown and which maybe of circular, oval, irregular or any other desired shape and sizeaccording to the casting which is to be produced and the cavity or moldmay be maintained by means of a gasifiable or vaporizable material. Itis to be understood that the particular mold cavity illustrated in thedrawing constitutes no limitation on the invention, but is purely forpurpose of exemplification. The casting box 1 is supported by andconnected to pivots 19,20 in the form of double columns 21,22 supportedon base members 8,9 rising from a base surface or the ground and havingas parts thereof the pole shoes 5,6 by means of the nonmagnetic guides15,16 and this whole arrangement is movable or displaceableperpendicularly to the plane of the drawing in FIG. 1 by means ofrollers 2 in a manner per se known.

The casting material 3 with its cavity or mold 4 are movable withcasting box 1 with relation to the pole shoes 5,6 which form part of theelectromagnet 7 and there is a transverse member shown extending betweenpivots 19,20 around which and in the space therebetween under thecasting box 1 and rollers 2 it is connected by a field coil 10 which isa part of the electromagnet 7 and this field coil 10 is provided withsuitable circuitry 11,12 as shown which connects the electromagnet andits field coil with a source of current (not shown). It is further to beobserved that adjustable permanent magnets 13,14 are arranged parallelto the axes of the rollers 2, the magnet designated 13 being inoperating position, whereas the magnet designated 14 has been displacedsomewhat to make it possible to remove the casting box 1 from the poleshoes 5 ,6 of the electromagnet 7 after the current supply has beendiscontinued. It will further be noted that pole shoes 5,6 of the electromagnet 7 and the pole shoes of the permanent magnets 13,14 haveexchangeable or replaceable non-magnetic guides heretofore referred toas 15,16 (FIG. 1) and additional nonmagnetic guides 17,18 (FIG. 2) Bymeans of the guides 15,16 casting box 1 can he slid or moved relative torollers 2 in order to bring it to the correct distance from pole shoes5,6 at the time it is moved between those pole shoes for commencing thecasting operation. In contrast, guides 17,18 maintain the permanentmagnets 13,14 at the prescribed distance from casting box 1.

The pivots 19,20 above referred to in connection with the double columns21, 22 contain surface markings thereon (in FIG. 1) which have thesignificance that the strength of the magnetic field can be increased ordecreased depending upon the mold cavity and the shape of the article orobject to be cast and this is accomplished by relative shifting orrearrangement of the pole shoes 5,6 of electromagnet 7. The amount andnature of re-arrangement is not only dependent upon the size and shapeof the object or article to be cast, i.e. the configuration of the moldcavity, but the principles for doing this are themselves per se known.

It will, therefore, be seen that the invention obviates the necessity ofusing induction coils and moving them relative to the casting materialand provides a superior and more economical casting device and methodwherein relatively inexpensive and simple permanent magnets orelectromagnets are employed which are easily adjustable in relation tothe casting box for changing the field strength acting on the parti cleswhich are to be cast magnetically. Further advantage accrues in that itbecomes possible with the present device to move the casting box whenmovement is required along a path which is level or substantially levelthereby avoiding raising and lowering operations either of the castingbox or the previously employed induction coils and this is especiallyadvantageous when it is realized that the casting box may be relativelylarge and may contain a great amount of loose magnetizable particles andfurthermore when the casting has been completed, the movement of thecasting box is simple and easily carried out.

By way of example and without limiting the invention thereto, it ispreferred to make casting box 1 of sheet iron or steel plate and thecasting material 3 is formed of round steel grits of 0.2 to 2 mm indiameter. The vaporizable or gasifiable mold 4 is composed of foamedpolystyrene. The preferred form of magnet is illustrated in the drawingwherein the electromagnets are supplied with direct current and have amagnetic flux of 10,000 to 12,000 gausses and an air gap of 1,500gausses.

What is claimed is:

l. A device for magnetic casting in a casting box movable on rollers,comprising a casting box having a mold cavity formed in mold material ofloose magnetizable particles and in which material the cavity ispreserved until formation of a supporting wall thickness of casting bythe action of magnetic forces, a stationary electromagnet to generatemagnetic casting forces, a field coil for the electromagnet arrangedbelow the rollers supporting the casting box and pole members for saidelectromagnet adjustable parallel to the direction of motion of thecasting box at a distance therefrom on pivots and additional magnetsenclosing the casting box displaceable perpendicularly to the directionof travel of the casting box to the extent that the casting box isadvanced on the rollers.

2. A device for magnetic casting according to claim 1, whereinnon-magnetizable particles are intermixed with magnetizable particles.

3. A device for magnetic casting according to claim 1, wherein guides ofnon-magnetic material extend from the casting box to the pole members ofthe magnets.

4. A device for magnetic casting according to claim 3, wherein theguides are on the magnets and one magnet is a stationary electromagnetthe surfaces of whose pole members are parallel to the direction ofmotion of the casting box, said magnet being provided with a yoke andfield coil located underneath the rollers.

5. A device for magnetic casting according to claim 1, wherein permanentmagnets displaceable perpendicular to the direction of movement of thecasting box are arranged for one to be moved in front of and the otherto be moved behind the casting box.

1. A device for magnetic casting in a casting box movable on rollers,comprising a casting box having a mold cavity formed in mold material ofloose magnetizable particles and in which material the cavity ispreserved until formation of a supporting wall thickness of casting bythe action of magnetic forces, a stationary electromagnet to generatemagnetic casting forces, a field coil for the electromagnet arrangedbelow the rollers supporting the casting box and pole members for saidelectromagnet adjustable parallel to the direction of motion of thecasting box at a distance therefrom on pivots and additional magnetsenclosing the casting box displaceable perpendicularly to the directionof travel of the casting box to the extent that the casting box isadvanced on the rollers.
 2. A device for magnetic casting according toclaim 1, wherein non-magnetizable particles are intermixed withmagnetizable particles.
 3. A device for magnetic casting according toclaim 1, wherein guides of non-magnetic material extend from the castingbox to the pole members of the magnets.
 4. A device for magnetic castingaccording to claim 3, wherein the guides are on the magnets and onemagnet is a stationary electromagnet the surfaces of whose pole membersare parallel to the direction of motion of the casting box, said magnetbeing provided with a yoke and field coil located underneath therollers.
 5. A device for magnetic casting according to claim 1, whereinpermanent magnets displaceable perpendicuLar to the direction ofmovement of the casting box are arranged for one to be moved in front ofand the other to be moved behind the casting box.